import random
import string

def generate_test_cases(num_cases=5):
    """生成测试用例"""
    test_cases = []
    
    # 生成一些简单的测试用例
    test_cases.extend([
        "aab",  # 示例1
        "a",    # 示例2
        "aaa",  # 全相同字符
        "aba",  # 简单回文
        "abba"  # 偶数长度回文
    ])
    
    # 生成一些随机测试用例
    for _ in range(num_cases):
        length = random.randint(1, 10)
        s = ''.join(random.choices(string.ascii_lowercase, k=length))
        test_cases.append(s)
    
    return test_cases

if __name__ == "__main__":
    test_cases = generate_test_cases()
    print("生成的测试用例：")
    for i, case in enumerate(test_cases, 1):
        print(f"测试用例 {i}: {case}") 